1. Field of the Invention
The invention relates to a method of treating a lung having at least one symptom of reversible obstructive pulmonary disease, and more particularly, the invention relates to advancing a treatment device into the lung and treating the lung with the device to at least reduce the ability of the lung to produce at least one of the symptoms of reversible obstructive pulmonary disease. The invention includes additional steps that reduce the ability of the lung to produce at least one of the symptoms of reversible obstructive pulmonary disease and to reduce the resistance to the flow of air through a lung.
2. Brief Description of the Related Art
Reversible obstructive pulmonary disease includes asthma and reversible aspects of chronic obstructive pulmonary disease (COPD). Asthma is a disease in which (i) bronchoconstriction, (ii) excessive mucus production, and (iii) inflammation and swelling of airways occur, causing widespread but variable airflow obstruction thereby making it difficult for the asthma sufferer to breathe. Asthma is a chronic disorder, primarily characterized by persistent airway inflammation. However, asthma is further characterized by acute episodes of additional airway narrowing via contraction of hyper-responsive airway smooth muscle.
The reversible aspects of COPD generally describe excessive mucus production in the bronchial tree. Usually, there is a general increase in bulk (hypertrophy) of the large bronchi and chronic inflammatory changes in the small airways. Excessive amounts of mucus are found in the airways and semisolid plugs of mucus may occlude some small bronchi. Also, the small airways are narrowed and show inflammatory changes. The reversible aspects of COPD include partial airway occlusion by excess secretions, and airway narrowing secondary to smooth muscle contraction, bronchial wall edema and inflation of the airways.
In asthma, chronic inflammatory processes in the airway play a central role in increasing the resistance to airflow within the lungs. Many cells and cellular elements are involved in the inflammatory process, particularly mast cells, eosinophils T lymphocytes, neutrophils, epithelial cells, and even airway smooth muscle itself. The reactions of these cells result in an associated increase in the existing sensitivity and hyper-responsiveness of the airway smooth muscle cells that line the airways to the particular stimuli involved.
The chronic nature of asthma can also lead to remodeling of the airway wall (i.e., structural changes such as thickening or edema) which can further affect the function of the airway wall and influence airway hyper-responsiveness. Other physiologic changes associated with asthma include excess mucus production, and if the asthma is severe, mucus plugging, as well as ongoing epithelial denudation and repair. Epithelial denudation exposes the underlying tissue to substances that would not normally come in contact with them, further reinforcing the cycle of cellular damage and inflammatory response.
In susceptible individuals, asthma symptoms include recurrent episodes of shortness of breath (dyspnea), wheezing, chest tightness, and cough. Currently, asthma is managed by a combination of stimulus avoidance and pharmacology.
Stimulus avoidance is accomplished via systematic identification and minimization of contact with each type of stimuli. It may, however, be impractical and not always helpful to avoid all potential stimuli.
Asthma is managed pharmacologically by: (1) long term control through use of anti-inflammatories and long-acting bronchodilators and (2) short term management of acute exacerbations through use of short-acting bronchodilators. Both of these approaches require repeated and regular use of the prescribed drugs. High doses of corticosteroid anti-inflammatory drugs can have serious side effects that require careful management. In addition, some patients are resistant to steroid treatment. The difficulty involved in patient compliance with pharmacologic management and the difficulty of avoiding stimulus that triggers asthma are common barriers to successful asthma management.
Asthma is a serious disease with growing numbers of sufferers. Current management techniques are neither completely successful nor free from side effects.
Accordingly, it would be desirable to provide an asthma treatment which improves airflow without the need for patient compliance.
In addition to the airways of the lungs, other body conduits such as the esophagus, ureter, urethra, and coronary arteries, are also subject to periodic reversible spasms that produce obstruction to flow.
The present invention relates to methods for treating a lung, preferably having at least one symptom of reversible obstructive pulmonary disease, comprising the steps of advancing a treatment device into the lung and treating the lung with the device to at least reduce the ability of the lung to produce at least one symptom of reversible obstructive pulmonary disease and to decrease the resistance to the flow of air through the lung.
A variation of the invention includes the method described above further comprising the step of locating one or more treatment sites within an airway of the lung, selecting at least one of the treatment sites and treating at least one of the treatment sites selected in the selecting step. The invention may further include performing the steps while the lung is experiencing at least one symptom of either natural or artificially induced reversible obstructive pulmonary disease.
A further variation of the invention includes the method described above and further includes the steps of testing the lung for at least one pre-treatment pulmonary function value prior to the treating step, and re-testing the lung for at least one post-treatment pulmonary function value subsequent to the treating step.
A further variation of the invention includes the method described above further comprising identifying treatment sites within the airway being highly susceptible to either airway inflammation, airway constriction, excessive mucus secretion, or any other symptom of reversible obstructive pulmonary disease.
Another variation of the invention includes the method described above and the additional step of stimulating the lung to produce at least one artificially induced symptom of reversible obstructive pulmonary disease. The invention may further comprise the step of evaluating the results of the stimulating step.
Another variation of the invention includes the method described above where treating at least airway tissue within the lung further comprises the step of determining the effect of the treatment by visually observing the airway for blanching of airway tissue.
Another variation of the invention includes the method described above where treating at least airway tissue at a treatment site within the lung further comprises the step of monitoring electrical impedance of tissue at one or more points.
Another variation of the invention includes the method described above where treating the lung includes sub-mucosal treatment of at least airway tissue in the lung.
Another variation of the invention includes the method described above where the treating step includes treating the lung by depositing a radioactive substance in at least one treatment site within the lung.
Another variation of the invention include the method described above further including the step of scraping tissue from a wall of an airway within the lung prior to the treating step. The invention may further comprise depositing a substance on the scraped wall of the airway.
Another variation of the invention includes the method described above where the treating step uses a modality selected from the group consisting of mechanical, chemical, radio frequency, radioactive energy, heat, and ultrasound.
Another variation of the invention includes the method described above further comprising pre-treating the lung to at least reduce the ability of the lung to produce at least one symptom of reversible obstructive pulmonary disease prior to the treating step, where at least one parameter of the pre-treating step is lesser than at least one parameter of the treating step.
Another variation of the invention comprises the method described above where the treating step includes separating the treating step into stages to reduce the healing load on the lung. The separating step may comprise treating different regions of the lung at different times or dividing the number of treatment sites into a plurality of groups of treatment sites and treating each group at a different time.
Another variation of the invention includes the method described above further comprising sensing movement of the lung and repositioning the treatment device in response to said sensing step.
Another variation of the invention includes the method described above further comprising reducing the temperature of lung tissue adjacent to a treatment site.
Another variation of the invention includes the method described above further comprising the step of providing drug therapy, exercise therapy, respiratory therapy, and/or education on disease management techniques to further reduce the effects of reversible obstructive pulmonary disease.
The invention further includes the method for reversing a treatment to reduce the ability of the lung to produce at least one symptom of reversible obstructive pulmonary disease comprising the step of stimulating re-growth of smooth muscle tissue in the lung.
The invention further includes the method of evaluating an individual having reversible obstructive pulmonary disease as a candidate for a procedure to reduce the ability of the individual""s lung to produce at least one reversible obstructive pulmonary disease symptom by treating an airway within the lung of the individual, the method comprising the steps of assessing the pulmonary condition of the individual, comparing the pulmonary condition to a corresponding predetermined state; and evaluating the individual based upon the comparing step. The method may additionally comprise the steps of performing pulmonary function tests on the individual to obtain at least one pulmonary function value, comparing the at least one pulmonary function value to a corresponding predetermined pulmonary function value, and evaluating the individual based upon the comparing step.
The invention further comprises a method of evaluating the effectiveness of a procedure to reduce the ability of lung to produce at least one symptom of reversible obstructive pulmonary disease previously performed on an individual having reversible obstructive pulmonary disease, the method comprising the steps of assessing the pulmonary condition of the individual, comparing the pulmonary condition to a corresponding predetermined state; and evaluating the effectiveness of the procedure based upon the comparing step. The method may additionally comprise the steps of performing pulmonary function tests on the individual to obtain at least one pulmonary function value, treating the lung to at least reduce the ability of the lung to produce at least one symptom of reversible obstructive pulmonary disease, performing post-procedure pulmonary function tests on the individual to obtain at least one post-procedure pulmonary function value; and comparing the pulmonary function value with the post-procedure pulmonary function value to determine the effect of the treating step.